1. Field of the Invention
The present invention relates to a dielectric color filter of an AC driven plasma display panel, and more particularly, to a dielectric color filter integrating a function of a transparent dielectric layer and that of a color filter among elements constructing an upper panel of a PDP, a method for fabricating the same, and a PDP panel using the same.
2. Description of the Background Art
FIG. 1 is a schematic view showing an AC driven plasma display panel (referred to as xe2x80x98PDPxe2x80x99, hereinafter) in accordance with a conventional art.
As shown in the drawing, an upper panel 100 and a lower panel 200 are separately fabricated and then attached to form a PDP.
The upper panel 100 includes a sustain electrode 2 formed on a front glass substrate 1 by vacuum coating, a glassy transparent dielectric layer 3 that is formed to limit current flowing in AC driving; and a protective film 4. As an oxide formed by vacuum deposition process, the protective film 4 protects the transparent dielectric layer 3 when gas is discharged and discharges surface electron to thereby lower a discharge voltage.
The lower panel 200 includes an address electrode formed on the upper surface of a rear glass substrate 5; a barrier rib 7 made of a black oxide, formed on the upper portion of the rear substrate and between the address electrodes 6; and a discharge cell 8 defined by the barrier ribs 7. The lower panel 200 also includes a fluorescent layer 9 formed on the side face and the bottom face of the discharge cell 8 by screen printing process. The fluorescent layer 9 radiates red color, green color and blue color.
The upper panel 100 and the lower panel 200 are attached to seal the discharge cell 8 which is filled with a mixture gas of xenon (Xe) and neon (Ne).
The operational principle of the PDP constructed as described above will now be explained.
When an AC power source is applied to the two electrodes 2 and 6, ultraviolet rays are generated from the xenon gas in the discharge cell due to a discharge phenomenon. The generated ultraviolet rays excite the fluorescent layer 9, so that a visible ray 10 of red color, green color and blue color that is capable of display characters or pictures is radiated externally from the front glass substrate.
However, the conventional PDP as described above has the following problems. That is, as state above, the discharge cell 8 is filled with the neon gas for lowering the discharge voltage and stabilizing discharging together with the xenon gas, a discharge gas. In this respect, however, the neon gas generates a orange-colored visible ray of which wave length of 585 nm when discharging occurs in the discharge cell, which degrades color purity and contrast of the PDP.
That is, since the orange color is mixed with the fluorescent color of the red, green and blue fluorescent material, the colors are not accurately reproduced.
In addition, the current technique fails to provide a satisfying level for reproducing the red, green and blue color perfectly. Besides, external light is considerably reflected on the surface of the panel.
With the PDP aiming at a wall type TV set for home use or a wide view monitor, the orange-colored light, the color purity related matter of the visible ray, the surface reflection of the external light are closely related to the display quality of the PDP, and in this sense, they negatively work on the PDP by degrading the contrast of the PDP.
In an effort to resolve the problems, a PDP having color filters as shown in FIG. 2 has been proposed.
FIG. 2 is a sectional view of an upper panel of an AC driven PDP adopting color filters in accordance with a conventional art.
As shown in the drawing, in order to improve the contrast, a red color filter 11, a green color filter 12 and a blue color filter 13 are thickly formed and sintered by screen printing between the, sustain electrode 2 and the dielectric layer 3, and a transparent glass or a black-colored glass 14 is filled between the color filters 11, 12 and 13.
As a material for the red color filter 11, an ferrite oxide inorganic pigment is typically used, and as a material for the red color filter 12 and the blue color filter 13, an inorganic pigment such as a cobalt oxide is typically used.
In case of screen printing, the inorganic pigment is mixed with a low-temperature degradable resin such as ethyl cellulose and organic solvent such as butyl carbitol acetate to obtain a paste, and then the red, green and blue color filters are thickly formed and sintered sequentially for three times.
Nevertheless, the PDP having color filters with the structure as shown in FIG. 2 exposes the following problems. That is, since the color filters for the PDP fabricated in the screen printing method in the conventional art should undergo thermal treatment of three times of sintering, the fabrication process is lengthened, consuming more materials, which causes an increase in a production cost and limitation for fabricating a large-scaled PDP.
In addition, the thermal treatment may cause a change in thermal and electrical characteristics of the front glass substrate 1 and the sustain electrode 2, or a chemical reaction may occur between the sustain electrode 2 and the transparent dielectric layer 3, which would shorten the durability of the display panel.
Therefore, an object of the present invention is to provide a dielectric color filter for a PDP integrating a dielectric layer and a color filter, and a method for fabricating the same.
Another object of the present invention is to provide a dielectric color filter for a PDP that is capable of remarkably improving color purity and contrast by blocking an orange-colored light radiated from a neon discharge gas, and a method for fabricating the same.
Still another object of the present invention is to provide a dielectric color filter for a PDP for which a transparent dielectric layer and a color filter are integratedly constructed to simplify its fabricating method, to reduce a production cost and to accomplish an excellent visible ray filter function, and a method for fabricating the same.
Yet another object of the present invention is to provide a PDP panel in which a dielectric color filter is used as a dielectric layer.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a dielectric color filter for a PDP for which neodymium oxide (Nd2O3), rare earth oxide, is added to an oxide dielectric solid powder having lead glass as a primary ingredient, a resulted material of which is melted and sintered to obtain a dielectric paste, and then the dielectric paste is coated by screen printing process and then sintered.
In order to achieve the above objects, there is also provided a dielectric color filter for a PDP for which neodymium oxide (Nd2O3) and praseodymium oxide (Pr2O3), each rare earth oxide, are added to an oxide dielectric solid powder having lead glass as a primary ingredient, a resulted material of which is melted and sintered to obtain a dielectric paste, and then the dielectric paste is coated by screen printing process and then and sintered.
In order to achieve the above objects, there is also provided a dielectric color filter for a PDP of which addition amount of each of neodymium oxide (Nd2O3) and praseodymium oxide (Pr2O3) for fabricating the dielectric color filter for a PDP is about 1xcx9c5 wt % to the oxide dielectric solid powder.
In order to achieve the above objects, there is also provided a method for fabricating a dielectric color filter for a PDP including the steps of: adding a neodymium oxide (Nd2O3), rare earth oxide, to an oxide dielectric solid powder having lead glass as a primary ingredient, to fabricate a mixture solid powder; melting and sintering the mixture solid powder in a platinum furnace at a temperature of about 1,100xc2x0 C., to form synthetic glass; mixing the synthetic glass with terpineol organic solvent and ethyl cellulose resin, to obtain a dielectric color filter paste; and screen-printing the paste between a sustain electrode and a protective film of an upper panel of a PDP.
In order to achieve the above objects, in the step of fabricating the mixture solid powder of the method for fabricating a dielectric color filter for a PDP, praseodymium oxide (Pr2O3), rare earth oxide, is additionally mixed.
In order to achieve the above objects, there is also provided an AC driven PDP panel including a sustain electrode displayed on a substrate; a dielectric layer formed on the sustain electrode; and a protective film formed on the dielectric layer, of which the dielectric layer is functioned as a color filter for filtering a light of a specific wave length.
In order to achieve the above objects, the dielectric layer of the PDP panel refers to a dielectric color filter including a material for color filtering.
In order to achieve the above objects, the dielectric layer of the PDP panel is formed by repeatedly screen printing dielectric paste for several times, of which one process is for printing a dielectric color filter paste including a color filter.
In order to achieve the above objects, the dielectric layer of the PDP panel is formed by adding neodymium oxide and praseodymium oxide to oxide dielectric.